Specifications

Best Practices for Virtualizing and Managing Exchange 2013

Page File Guidance

When a machine runs low on memory and needs more immediately, the operating system uses hard disk

space to supplement system RAM through a procedure called paging. Too much paging degrades overall

system performance. However, you can optimize paging by using the following best practices and

recommendations for page file placement.

Best Practices and Recommendations

Let the Windows Server 2012 Hyper-V host operating system handle the page file sizing. It is well

optimized in this release.

Isolate the page file on its own storage devices, or at least make sure it does not share the same

storage devices as other frequently accessed files. For example, place the page file and operating

system files on separate physical disk drives.

Place the page file on a drive that is not fault-tolerant. Note that if the disk fails, a system crash is

likely to occur. If you place the page file on a fault-tolerant drive, remember that fault-tolerant

systems are often slower to write data because they do so to multiple locations.

Use multiple disks or a disk array if you need additional disk bandwidth for paging. Do not place

multiple page files on different partitions of the same physical disk drive.

The following additional best practices and recommendations should be considered while planning and

managing host compute (CPU and memory) resources.

Best Practices and Recommendations

While performing capacity planning for virtualizing workloads, always count the number of cores

required and not the number of logical processors/threads required.

Note: Dynamic Memory is not supported for Exchange 2013 and is not NUMA-aware. When

you are planning how to use the host server’s memory, it is important to consider the

virtualization-related overhead. Whether you choose to use NUMA and/or Dynamic Memory, both

have some overhead related to memory management in the virtualized environment. There may

be scenarios when using NUMA and/or Dynamic Memory may not be the best option. For

Exchange Server, memory allocations must be statically configured. Properly plan the memory

requirements for running Exchange 2013 workloads on Windows Server 2012, and do not

use Dynamic Memory for Exchange 2013 virtual machines. (For more information, see our

NUMA best practices and recommendations).

There is an additional load on root server processors because the root servers manage running

guest machines. This overhead varies in different scenarios; however, it is good to consider some

percent of overhead when planning/sizing the host processors.